Search for the Critical Point of Quantum Chromodynamics (QCD)

相对论核-核碰撞创造了一个由融合的高能量密度物质组成的短暂复合系统(Hagedorn火球)，其性质反映在实验观察到的终态中嵌入的大量可观察到的物理中。最近在非微扰晶格量子色动力学(QCD)方面的一项突破导致了关于QCD相图中的部分子-强子共存线的详细预测，特别是在(，T图中似乎显示了一个临界点。此外(有待进一步的晶格技术改进)，这一点似乎出现在300((B(450 MeV，相当于2002年结束的CERN SPS实验的较低能区)7((10GeV)。对这一能量区间的新兴趣使我们建议恢复相应的NA49数据(各种SPS能量下的铅+铅)，这些数据要么以前没有被分析过，要么还没有最终的形式。临界点(和在(&gt；(CRIT)处发生的一阶部分子强子相变)的物理性质表明，通过事件涨落分析，例如事件横向动量&lt；pT&gt；、介子和介子多重数密度，以及几种奇异粒子产生的比率，如事件方向的K/(和K/p比)。NA49的广泛接受度和高强子辨别能力(一直持续到2002年)使这些数据分析特别有希望。

Relativistic nucleus-nucleus collisions create a short-lived compound system (the Hagedorn fireball) of fused, high energy density matter, the properties of which being reflected in a multitude of physics observable as imbedded in the experimentally observed final state. A recent breakthrough in non-perturbative lattice Quantum Chrome-dynamics (QCD) has led to detailed predictions concerning the parton-hadron coexistence line in the QCD phase diagram which, in particular, seems to exhibit a critical point in the (, T-diagram. Moreover (pending further lattice technical refinement) this point appears to occur in the interval 300 ( (B ( 450 MeV that corresponds to the lower energy domain of the CERN SPS experiments (7 ( ( 10 GeV) that ended in 2002. The renewed interest in this energy interval leads us to propose revisting the corresponding NA49 data (Pb+Pb at various SPS energies) which either have not been previously analyzed, or are not yet in their final form. The physics of the critical point (and the first order parton hadron phase transition occurring at ( > (crit) suggest event by event fluctuation analysis, e.g. of the eventwise transverse momentum < pT >, the pion and kaon multiplicity density, as well as several ratios of nonstrange to strange particle production like the eventwise K/( and K/p ratios. The large acceptance and the high hadron discrimination power of NA49 (which ran until 2002) make these data analysis particularly promising.